Answer:
Its C2H2
Explanation: ON EASTSIDE IT IS
What physical force can cause a change in the state of matter?
Helium is used in balloons because it is
a. reactive with rubber.
b. lighter than air.
c. flammable.
d. a colored gas
Final answer:
Helium is used in balloons because it is lighter than air and safely floats due to its low density and nonreactive, nonflammable properties. So the correct option is b.
Explanation:
Helium is used in balloons because it is lighter than air. This is due to helium's much lower density and atomic mass compared to the average molar mass of air. Helium's atomic mass is approximately 4.00 g/mol, while air has an average molar mass of about 29 g/mol. Hence, when a balloon is filled with helium, it floats. Another critical property of helium that makes it the gas of choice for balloons is its nonreactivity. Helium is chemically non-reactive and nonflammable, which contrasts with hydrogen, another light gas that is, however, highly flammable. This property of helium makes it safe for use in various applications like balloons, airships, and blimps. Furthermore, in environments where there is a high risk of fire or explosion, such as in welding, helium serves as an inert protective atmosphere. Finally, for deep-sea divers who operate under high pressure, a mixture of oxygen and helium is essential to avoid nitrogen narcosis, commonly known as the “rapture of the deep”.
The reactiveness of nonmetals depends on the atom's ability to what?
The ability of an atom to GAIN
If approximately equal volumes of an acid and a base of equal strengths are combined, the resulting solution should have a pH of _____.
Answer : The resulting solution will have a pH of 7.
Explanation:
Whenever acid and base reacts with each other to form water molecule is called Neutralization reaction. This water molecules is formed from the hydronium ion ([tex]H^+[/tex]) from acid and hydroxide ion([tex]OH^-[/tex]) from base.
When the equal volumes of acid and base of equal strength are combined, the resulting pH of the solution becomes 7.
The pH 7 value means that the solution is neutral.
what is the mass of 5 moles of Fe203?
To find the mass of 5 moles of Fe₂O₃, multiply its molar mass (159.70 g/mol) by 5, resulting in 798.5 grams. This calculation uses the molar mass of the elements iron and oxygen.
To find the mass of 5 moles of Fe₂O₃, we need to use the molar mass of the compound. Fe₂O₃ has the following molar mass:
Fe: 55.85 g/mol
O: 16.00 g/mol
Since there are 2 iron atoms and 3 oxygen atoms in Fe₂O₃, the calculation is:
2 × 55.85 g/mol + 3 × 16.00 g/mol = 159.70 g/mol
Now, multiply the molar mass by the number of moles:
159.70 g/mol × 5 mol = 798.5 g
Therefore, the mass of 5 moles of Fe₂O₃ is 798.5 grams.
Kumar is producing the photoelectric effect by using red light. He wants to increase the energy of emitted electrons. Based on the research of Albert Einstein, what is the best way for him to do this?
Explanation:
Photoelectric effect: Electrons are ejected out from the surface of metal when light of sufficient frequency falls upon shiny surface of metals. light is made up small bundles of energy packets named photons which when falls on surface transfer their energy to electrons due which electrons ejects out of the metallic surface. The energy for one photon was given by expression:
E=h[tex]\nu[/tex], or [tex]E\propto \nu[/tex]
h=Planck's constant, [tex]\nu[/tex]= frequency of the light
Kumar can increase the energy of emitted electron by using light with higher value of frequency than the frequency of red light. This is because the energy carried by the photon of a light is directly proportional to the frequency of the light. Higher the value of frequency of light higher will be the value of energy of a photon. And photon with higher energy will impart more amount of energy to an electron while ejection.
An unknown compound contains only carbon, hydrogen, and oxygen (CxHyOz). Combustion of 2.50g of this compound produced 3.67g of carbon dioxide and 1.50g of water.
How many moles of carbon, C, were in the original sample?
Final answer:
To find the moles of carbon in the original unknown compound, we use the mass of the carbon dioxide produced from combustion, and divide by its molar mass. This gives us the moles of carbon dioxide, which are equivalent to the moles of carbon in the sample, resulting in 0.0834 mol of carbon.
Explanation:
To determine how many moles of carbon, C, were in the original 2.50g sample of an unknown compound after combustion, we need to use the mass of carbon dioxide (CO2) produced. Every mole of CO2 contains one mole of C, so the moles of C are equal to the moles of CO2.
First, calculate the moles of CO2 using its molar mass:
Moles of CO2 = mass of CO2 / molar mass of CO2
Molar mass of CO2 is approximately 44.01 g/mol
Moles of CO2 = 3.67 g / 44.01 g/mol = 0.0834 mol
Since each mole of CO2 represents one mole of carbon, the moles of carbon in the original compound is also 0.0834 mol.
what property do atoms of these elements have that helps make the molecules polar
How is the evidence from a fire scene collected? What should be avoided?
Answer:
Explanation:
In fire and arson cases evidences like volatile fuel in the sediment debris can be collected. The debris should be collected in an air-tight container like tin or paint box and bottles so as to prevent the evaporation of the fuel. The type of fuel used for setting up the fire is an important evidence.
Plastic bags should not be used because the plastic can react with the fuel components and may react with the fuel components in debris and the evidence will become futile.
Milk of magnesia is _____.
an acid
a base
a neutral
Final answer:
Milk of magnesia is a base with a pH greater than 7, specifically around 10.5, making it effective as an antacid. It contrasts with neutral substances, like water, and acidic substances, like wine.
Explanation:
Milk of magnesia is a base. This determination is based on its pH level, which is greater than 7. Specifically, milk of magnesia, which is largely comprised of magnesium hydroxide (Mg(OH)2), has a pH of approximately 10.5. This high pH level classifies it as a basic substance, meaning it has properties that counteract acids. This characteristic is why milk of magnesia is commonly used as an antacid to neutralize stomach acid and alleviate symptoms of indigestion and heartburn.
In comparison, substances with a pH of 7, such as pure water, are considered neutral, neither acidic nor basic. Substances like wine, with a pH less than 7, are classified as acidic. Understanding the pH scale and the properties of acids and bases is essential in chemistry and various practical applications, including medicine and nutrition.
As the concentration of a given salt solution increases, the conductivity of the solution:
a) increases
b) no way to predict
c) remains the same
d) increases then decreases
decreases ...?
Answer: Option (a) is the correct answer.
Explanation:
Conductivity of a solution depends number of ions present in the solution. As these ions move from one place to another and thus there will be easily flow of current.
So, when there is increase in concentration then it means there are moer number of ions present into the solution.
Thus, conductivity will also increase due to increase in concentration of salt solution.
The heat of fusion for water at its normal freezing or melting temperature is L=333 kJ/kg. How much water remains unfrozen after 50.2 kJ is transferred as heat from 260 g of liquid water initially at its freezing point? ...?
The heating curve below shows the temperature change that occurs as a solid is heated. What is occurring at segment DE of the graph?
Melting
freezing
boiling
Which coefficients balance the following equation __ N2+___H2--->___NH3
A dilute, aqueous potassium nitrate solution is best classified as a
(1) homogeneous compound
(2) homogeneous mixture
(3) heterogeneous compound
(4) heterogeneous mixture
A dilute, aqueous potassium nitrate solution is classified as a homogeneous mixture, as it is a uniform mixture of solute and solvent at the molecular level.
Explanation:A dilute, aqueous potassium nitrate solution is best classified as a (2) homogeneous mixture, also known as a solution. This classification is due to the fact that potassium nitrate is a highly soluble ionic compound that, when dissolved in water, dissociates into ions, creating a mixture with a composition that is uniform throughout. Therefore, it is not possible to distinguish between the different components of the mixture, even with a powerful microscope. If we were talking about potassium hydroxide, it would similarly be fully soluble and dissociate completely, yielding a specified concentration of hydroxide ions in the case given. Nevertheless, for potassium nitrate, the dissolution would result in potassium and nitrate ions evenly distributed in the solution.
Which of the following elements would be the least likely to form a cation if involved in a chemical reaction?
chlorine (Cl)
potassium (K)
nitrogen (N)
fluorine (F)
Answer:
Fluorine (F) would be least likely to form a cation
Explanation:
A cation is a positively charged atom (or molecule) which has lost electron (or electrons). Electropositive elements show a greater propensity to lose electrons and form cations. These are usually metals that are present on the left of the periodic table.
Electropositivity or the tendency to lose electrons and form cations increases on going down a group and decreases across a period. In the given examples:
Potassium, K is an alkali metal and will lose electrons readily to form a cation
Nitrogen (N), Fluorine (F) and chlorine (Cl) are all non metals which prefer to accept electrons and form anions instead. Among the three, F is the most electronegative i.e. it will prefer to accept electrons and form F- rather than F+.
Suppose you wanted to calculate the heat of reaction for the formation of ammonia gas and gaseous hydrochloric acid from solid ammonium chloride.
a. Write a balanced equation for this reaction.
Answer:
Above is correct, but the heat of reaction is 176.18 J/mol
Explanation:
7.The _____ theory of matter states that all particles of matter are in constant motion.
(Fill in the blank)
The kinetic theory of matter states that all particles of matter are in constant motion.
The following are the postulates of kinetic theory of gases:
1. The particles of gases are in constant and random motion. Due to this motion, they collide with each other and walls of the container.
2. The particles of gases have point mass and zero volume.
3. The particles of gases have no such attraction or repulsion between them.
4. The kinetic energy with which the particles are moving is directly proportional to temperature. A temperature increases, kinetic energy also increases, and particles collide each other more frequently.
5. The particle of gases at given temperature have same kinetic energy.
Francium has the largest atomic radius. Why might this be?
A. The highest number of protons for the least number of electrons and neutrons.
B. The highest number of energy levels and the least nuclear pull.
C. The lower ability to gain or lose electrons resulting in fewer ions forming.
D. The highest number of energy levels most nuclear pull.
Francium has the largest atomic radius due to having the highest number of energy levels and the least nuclear pull.
Explanation:The correct answer is B. Francium has the largest atomic radius because it has the highest number of energy levels and the least nuclear pull. The atomic radius refers to the size of an atom, which is determined by the distance between the nucleus and the outermost electron shell.
Francium has the highest number of energy levels, which means the electrons are located farther from the nucleus, resulting in a larger atomic radius. Additionally, francium has the least nuclear pull, meaning the positive charge of the nucleus has less of an attraction on the outermost electrons, allowing them to spread out more.
Learn more about Francium atomic radius here:https://brainly.com/question/31977967
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Calculate the Cal(kcal) in 1 cup of whole milk: 12 g of carbohydrate, 9 g of fat, and 9 g of protein.
Answer:
165Kcal in a cup of whole milk
Explanation:
Hello! Let's solve this!
We know that 1g
carbohydrate = 4 Kcal
1g protein = 4Kcal
1g fat = 9Kcal
We do the conversion of each one
carbohydrates = 12g * 4Kcal * g = 48Kcal
Proteins = 9g * 4Kcal / g = 36Kcal
fat = 9g * 9Kcal / g = 81Kcal
We add all the results to have the total Kcal
48Kcal + 36Kcal + 81Kcal = 165Kcal in a cup of whole milk
Give the electron configuration for a neutral atom of manganese. Atomic number of Mn is 25.
calculate the frequency of red light with a wavelength of 6.50x10^-7
In a flame test experiment, Sodium gives the brightest and most persistent colour in the flame. Do you think that Potassium could be detected visually in the presence of Sodium, by heating this mixture in a flame? Explain your answer.
Yes, it is possible to visually detect the presence of potassium, even though sodium produces a brighter and more persistent color.
In a flame test experiment, the color observed in the flame is due to the excitation and subsequent relaxation of electrons in atoms or ions.
Each element has a unique set of energy levels, and when the electrons transition between these levels, they emit light of specific wavelengths, which we perceive as colors.
To enhance the visibility of potassium's flame color, one could adjust the experimental conditions, such as using a higher concentration of potassium or reducing the concentration of sodium.
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Final answer:
Potassium can be detected in the presence of sodium during a flame test by looking for its characteristic lilac color. Special equipment like spectrometers can enhance the detection of potassium's color in the flame test.
Explanation:
In a flame test experiment, when sodium is present, it can overwhelm other colors due to its bright yellow flame, which is highly persistent and intense. However, potassium can still be detected visually in the presence of sodium in a flame test. Potassium imparts a lilac color to the flame, which can be observed at the moment when the sodium's yellow emission fades, or by observing the edge of the flame where the color may be less intense. Additionally, the use of spectrometers or filters can help in better visualizing the potassium flame in the presence of sodium.
A molecule that can be used as a molecular clock has a neutral mutation rate of one mutation per 5 million years. How many years ago did two species share a common ancestor if the molecules found in these two species differ by a total of eight mutations?
Answer
1.5 million years
10 million years
20 million years
40 million years
...?
The two species diverged from a common ancestor approximately 40 million years ago, calculated by multiplying the total number of mutations (eight) by the mutation rate (one mutation per 5 million years).
Explanation:To estimate the time two species shared a common ancestor using a molecular clock, one must know the mutation rate and the number of mutations that have accumulated in both species since they diverged from a common ancestor. In the given problem, the molecule has a neutral mutation rate of one mutation per 5 million years. If the molecules in the two species differ by a total of eight mutations, the time since the common ancestor can be estimated by multiplying the number of mutations by the rate of mutation. Therefore, 8 mutations imes 5 million years per mutation equals 40 million years ago.
How many atoms are in 2.70 moles of iron (Fe) atoms?
4.48 × 10-24 atoms Fe
1.63 × 1024 atoms Fe
2.23 × 1023 atoms Fe
6.02 × 1023 atoms Fe
Avogadro's number is the number of units (atoms, molecules) in 1 mole of substance:
6.023 × 10²³ atoms per 1 moleWhat element behaves MOST like magnesium
between Si, S, Sr, Sn
Answer
SrExplanation
In periodic table, the elements have almost same properties are present in the same group. As Mg and Sr are present in group II-A, so both behave most likely to each other due to having same valence shell electrons as well.Si and Sn are present in group IV-A which have same behavior but different one from Mg due to different groups.S is present in group VI-A which show different properties from all others one especially from Mg.1.Which best explains why ionization energy tends to decrease from the top to the bottom of a group?
A.The number of orbitals decreases.
B.The number of neutrons decreases.
C.Electrons get closer to the nucleus.
D.Electrons get farther from the nucleus.
3.When electrons are removed from the outermost shell of a calcium atom, the atom becomes
A. an anion that has a larger radius than the atom.
B. an anion that has a smaller radius than the atom.
C. a cation that has a larger radius than the atom.
D. a cation that has a smaller radius than the atom.
Answer:
1) Electrons get farther from the nucleus.
2) a cation that has a smaller radius than the atom.
Explanation:
1) ionization energy is the energy required to remove the valence electron from an isolated gaseous atom of an element.
Thus it requires some energy to remove the electron as electrons are attracted towards nucleus (positive protons are present) due to nuclear charge.
As the size increases on moving top to bottom (due to more number of shells) the distance of electrons from the nucleus increases which decreases the effective nuclear charge on electrons, decreasing the ionization energy.
2) When an atom loses an electron it attains a positive charge and is known as cation.
A cation has smaller size than the neutral atom as the less electrons are attracted towards nucleus and thus feel more effective nuclear charge.
The answers are 1. The ionization energy tends to decrease from the top to the bottom of a group because D. Electrons get farther from the nucleus. 3. When electrons are removed from the outermost shell of a calcium atom, the atom becomes D. a cation that has a smaller radius than the atom.
The correct answer for question 1 is D. Electrons get farther from the nucleus best explains why ionization energy tends to decrease from the top to the bottom of a group
Ionization energy is the energy required to remove an electron from an atom in the gaseous state. As one moves down a group in the periodic table, the ionization energy tends to decrease. This is because each element down the group has an additional shell of electrons. The outermost electrons are farther from the nucleus, which means they experience a weaker effective nuclear charge. The increased distance from the nucleus and the screening effect of the inner electrons make it easier to remove an outer electron, thus decreasing the ionization energy.
The incorrect options can be explained as follows:
A. The number of orbitals increases, not decreases, as one moves down a group, which actually contributes to the decrease in ionization energy.
B. The number of neutrons generally increases as one moves down a group, but this does not directly affect the ionization energy.
C. Electrons do not get closer to the nucleus; in fact, they get farther away as additional electron shells are added, which is why the ionization energy decreases.
The correct answer for question 3 is D. a cation that has a smaller radius than the atom.
When electrons are removed from an atom, the atom becomes a cation (a positively charged ion). In the case of calcium, which has two electrons in its outermost shell, removing these electrons results in a Ca^2+ ion. Because the outermost electrons are no longer there to shield the nuclear charge, the remaining electrons are more strongly attracted to the nucleus. This causes the ion to have a smaller radius than the neutral atom.
The incorrect options can be explained as follows:
A. An anion is formed when an atom gains electrons, not when electrons are removed.
B. An anion would have a larger radius than the neutral atom because the added electrons increase repulsion and decrease the effective nuclear charge.
C. A cation has a smaller radius than the neutral atom, not a larger one, because the loss of electrons increases the effective nuclear charge, pulling the remaining electrons closer to the nucleus."
In the late 1890s, what objection might have been raised about Becquerel’s claim that the uranium salt crystals had emitted something that exposed the photographic film?
There was no apparent source for the uranium salts’ energy.
Film only becomes exposed in response to light.
Both the crystals and the film had been exposed to sunlight during the experiment.
The crystals began to phosphoresce in the drawer and release X-rays.
A- There was no apparent source for the uranium salts' energy (just took the edg test)
Answer:
The correct answer is "There was no apparent source for the uranium salts’ energy."
Explanation:
Becquerel while working on X-rays accidentally discovered radioactivity. While working with uranium salts he observed that it emitted penetrating radiation that exposed photographic film. His contemporaries did not know radioactivity and hence they believed that there was no apparent source for the uranium salts’ energy.
The 64.8-g sample of the compound X2O5 contains 48.0 g of oxygen atoms. What is the molar mass of element X?
Examine the equation.
CH4 + 2O2 → CO2 + __H2O
In order to balance the equation, what coefficient must be placed in front of H2O?
2
4
1
3
Answer:
[tex]\huge \boxed{\mathrm{2}}[/tex]
[tex]\rule[225]{225}{2}[/tex]
Explanation:
[tex]\sf CH_4+ O_2 \Rightarrow CO_2 + H_2O[/tex]
Balancing the Hydrogen atoms on the right side,
[tex]\sf CH_4+ O_2 \Rightarrow CO_2 +2 H_2O[/tex]
Balancing the Oxygen atoms on the left side,
[tex]\sf CH_4+ 2O_2 \Rightarrow CO_2 +2 H_2O[/tex]
[tex]\rule[225]{225}{2}[/tex]